Evaluation of two new types of filler for restorative composite resins is being conducted. One type of resin is a porous silica glass intended for anterior restorations where improved polishability is desired. The other is a porous surface nickel powder. This powder is intended to improve the wear resistance of posterior composite systems. A stylus abrasion tester has been constructed to determine the wear properties of the nickel composites. A wear stylus under a fixed load is placed in contact with a rotating sample and the abrasion of both the stylus and resin is evaluated at various time intervals. The abrader can be of natural teeth or other synthetic material. Preliminary tests are being conducted on amalgam and composite products whose wear rates had previously been published in order to determine the reliability of the apparatus. A BIS-GMA matrix has been formulated for use with experimental composites. Thermal coefficient of expansion measurements have been made and other tests are being conducted in order to throughly characterize the behavior of the laboratory composites. Experimental composites have been prepared and examined using light and scanning electron microscopy. These systems have utilized silane treated and non-treated porous glass fillers of two different pore sizes and an untreated nickel powder. Initial observation on the non-silane treated glass composite indicated the resin gives good particle retention and has completely penetrated the porous glass but may not have completely polymerized.